Device and method for controlling fluid flows in lab-on-a-chip systems and method for producing said device

ABSTRACT

An array of valves are arranged in n columns and m lines and which are each designed to control a fluid flow in an associated flow channel in a lab-on-a-chip system. The array includes at least two valves, every column having not more than one valve and every line having from zero to n valves. A device is used for actuating the valves. The valves are pressure-actuated. To produce the device, the flow channels are arranged in accordance with the arrangement of the valves.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national stage of International ApplicationNo. PCT/EP2010/055817, filed Apr. 29, 2010 and claims the benefitthereof. The International Application claims the benefits of GermanApplication No. 102009023430.6 filed on May 29, 2009, both applicationsare incorporated by reference herein in their entirety.

BACKGROUND

Described below is a device for controlling fluid flows in lab-on-a-chipsystems, using an array of valves. The valves are arranged in n columnsS_(n) and m rows Z_(m), n and m being integers. They are each configuredto control a fluid flow in an associated flow channel. The devicefurthermore includes an instrument for actuating the valves. A devicehaving the features described above is known, for example, from EP 0 180064 B1. Also described below are methods for controlling fluid flows insuch lab-on-a-chip systems and to methods for producing the device.

In biosensor technology, lab-on-a-chip systems are used in order to beable to carry out biochemical analyses in parallel. Microfluidicinstruments and a chip having an array of sensors are integrated on asupport, which for example may be a plastic card. The array of sensorsmay, for example, be formed by electrochemical sensors which arearranged in columns and rows on the chip. The sensors are coated withmolecules, to which the substances to be detected bind specifically. Thespecific binding is detected electrochemically by changes in currentand/or voltage. In this way, biochemical substances, for exampleantibodies, peptides or DNA, can be detected in solutions to beexamined, for example blood or urine.

The measured electrochemical signals may be processed directly byintegrated circuits on the chip, or they may be read out from the chipby an external evaluation unit. The chemicals required for theexamination may be delivered from the external evaluation unit to thesupport or they may already be on the support, for example in the formof dry reagents. During the examination, the solutions i.e. liquids aredelivered to the support and fed on the support via microchannels into areaction chamber. The chip with the sensor array is located in thereaction chamber. Reactions required for the detection may take place inthe microchannels and/or the reaction chamber.

In the case of complex biochemical reactions which are required for thedetection, the fluid flow of the solution must be controlled. Forinstance, it may be necessary for the liquid to stay for a predeterminedperiod of time in a region of the microchannels, so that for example dryreagents which are stored in this region are dissolved and chemicalreactions can take place. Only after completion of the chemicalreactions is the liquid fed further through the microchannel.Furthermore, when detecting biochemical substances in the reactionchamber it may be necessary to close the reaction chamber in afluid-tight fashion. To this end, valves are to be provided in thesupport. They are to be arranged at particular selected positions in thesupport, for example in the inlet and outlet of the reaction chamber.

EP 0 180 064 B1 discloses a valve array of valves which are designed toclose microchannels. The microchannels are arranged in a first support,which is covered with a thin membrane on one side of the microchannels.The thin membrane is arranged in a sandwich fashion between the firstsupport and a second support. Arranged in the second support, there areplunger-like instruments which can be pressed with the aid of springsvia the membrane onto openings of the microchannels in the firstsupport. The microchannels are thereby closed by the membrane. Thedescribed valves are arranged according to the position of the flowchannels on the support. They are driven individually and separatelyfrom one another.

In the case of complex analysis processes, it is indispensible to carryout a plurality of chemical processes separately from one anothersimultaneously on a chip card. To this end, a plurality of valves of anarray of valves on the chip card must be actuated simultaneously.Systems in the known art, as described for example in EP 0 180 064 B1,individually control the valves separately from one another, which isvery complicated and leads to high costs.

SUMMARY

Described below is a device having an array of valves, in which thevalves can be controlled simultaneously with a simple and economicalstructure. Also described below is a method which allows control of thevalves simultaneously according to a set program without elaborateelectronics and individual electrical driving of the valves. Alsodescribed below is a method for producing the array of valves, whichstarts on the basis of the arrangement of the valves.

The device for controlling fluid flows in lab-on-a-chip systems has anarray of valves, the valves being arranged in n columns S_(n) and m rowsZ_(m). In this case, n and m are integers. The array includes at leasttwo valves, each column S_(n) having no valve or at most one valve andeach row Z_(m) having between zero and n valves. The valves are eachconfigured to control a fluid flow in an associated flow channel. Thedevice furthermore includes an instrument for actuating the valves.

The special arrangement of the valves in the array makes simple controlpossible. In each column, there is only one valve. By virtue of anarbitrary number of valves in the rows, however, it is possible toachieve any required valve arrangement since the number of columns andthe number of rows are freely selectable. The array of valves can bedesigned according to the requirements of the chemical processes to becontrolled and therefore the fluidics in an analysis or examination, andthe time profile of the processes, in particular processes taking placesimultaneously at different positions. The fluidic channels and chambersare arranged in accordance with the design of the array of valves. Thearrangement of the valves in array form permits particularly simpleproduction, adaptable for many processes or reproducible, of the device.

The instrument for controlling the valves may have an essentially planeplate having elevations projecting from the plane, in which n′ columnsS_(n)′ and m′ rows Z_(m)′ are arranged. The spacings of neighboringcolumns S_(n)′ may in this case be equal to the spacings of associatedneighboring columns S_(n) of the valves.

The instrument for controlling the valves permits mechanical control ofall valves simultaneously according to a set program. Its structure inn′ columns S_(n)′ and m′ rows Z_(m)′ makes it compatible with the arrayof valves.

By mounting the essentially plane plate movably in a first directionrelative to the array of valves, the first direction extending parallelto the columns S_(n) of the array of valves, valves can be controlled bymoving the essentially plane plate. The elevations projecting from theplane of the plate may in this case on the one hand be arranged in n′columns S_(n)′ and m′ rows Z_(m)′ so that individual valves are closedor opened in a controlled way according to a predetermined programduring a movement of the essentially plane plate along the firstdirection relative to the array of valves.

Since only one valve is arranged in each column S_(n) of the array ofvalves, during movement of the plate along the gap an elevation in theessentially plane plate controls only this one valve. Depending on thespacing and number of elevations, the one valve can be opened andclosed. A plurality of elevations in a row lead to simultaneousactuation of valves arranged in a row. The arrangement of the valves andthe elevations therefore determines the program according to which thevalves are controlled. With a predetermined arrangement of the valves inthe array, the program can be determined by arrangement of theelevations.

The array of valves may be arranged in a chip card, the chip cardincluding a flat body made of a plastic material in credit card form, ona front side of which a film is applied, in particular a self-adhesivefilm. In the body, on the surface of the front side, flow channels maybe arranged as recesses, as well as the valves which contain anelastomer compound that is arranged at least partially next to arespectively associated flow channel. This provides a particularlysimple and economical to produce structure of the array of valves,especially since chip cards are common in biosensor technology and cantherefore be used in standard instruments. This likewise reduces costs,because it is not necessary to develop an entirely new concept of theanalysis instruments.

The plastic body may be formed of polycarbonate or polypropylene. Theelastomer may be a thermoplastic elastomer, in particular rubber or amixture of polypropylene and ethylene propylene diene M-class elastomer.These materials are easy to process and economical. They are also inertwith respect to most chemicals used in biosensor technology. Thesematerials furthermore do not react, or react only to a small extent,with the substances to be analyzed. Changes in the folding of thesubstances or molecules or other reactions, which vitiate theexamination, generally do not take place as a result of these materials.

The chip card may be arranged in a sandwich fashion in the instrumentfor actuating the valves. On a rear side of the chip card, a plunger foractuating the respective valve may respectively be arranged in aninstrument plate, the plunger being prestressed by at least one springbetween the instrument plate and the plunger so that essentially nopressure force exists between the plunger and the valve. Themechanically more complicated and therefore more cost-intensive part istherefore fitted in the instrument for actuating the valves. For adisposable chip card to be used once, it is thus possible to employinexpensive materials without an elaborate production process.

The sandwiched arrangement of the chip card in the instrument foractuating the valves leads to secure and positionally stable mounting,so that the chip card does not slip relative to the instrument. Thisensures that the plunger can reliably actuate the associated valve atany time. A reliable functionality is thereby ensured.

A method for controlling a device as described above includes actuationof the valves respectively by application of a pressure force, which isexerted in particular by at least one plunger, on the respective valve.When a pressure force is not applied a valve is opened and a fluid flowsin an associated flow channel, and when a pressure force is applied tothe valve the valve is closed and the fluid flow is prevented in theassociated flow channel.

This method is particularly simple and controls the liquid floweffectively. What is important in this case is that gas- and/orliquid-tight closure of the valve is ensured. The activation by apressure force permits a simple structure of the valve and theactivation action. A reliable functionality without fatigue of thematerials is feasible even with frequent opening and closing.

The opening and closing of the valves may be carried out according to apredetermined program by moving the essentially plane plate parallel tothe columns S_(n) relative to the array of valves.

No electrical programming or an elaborate regulating and control loopare necessary. In the case of a frequently executed analysis programwhich is always the same, this leads to a simple, reliable andeconomical structure and method. The control of the valves can becarried out exclusively mechanically, by movement of the essentiallyplane plate. Particularly in connection with the handling of liquids andthe laboratory environment, this leads to an increased reliability ofthe examination owing to less susceptibility to error compared withelaborate control electronics.

The difference between the m′ rows Z_(m)′ of the instrument forcontrolling the valves and the m rows Z_(m) of the array of valves candefine the number of process steps in which at least one valve isactuated.

A process involving control of the valves may on the one hand be carriedout by moving the essentially plane plate relative to the array ofvalves with a fixed speed, the duration of a process step beingdetermined by the spacing of the rows Z_(m′) from one another in thecase of an equal spacing of all rows Z_(m) respectively from oneanother, or the duration of a process step being determined by thespacing of the rows Z_(m) from one another in the case of an equalspacing of all rows Z_(m′) respectively from one another.

An essentially plane plate can reliably be operated with a constantspeed more simply and with less outlay than with accelerated speeds.Drives with a constant speed are economical and reliable. Determiningthe duration of the process steps by the spacing of the rows leads to ahigh reproducibility and reliability of the examination.

A process involving control of the valves may on the other hand becarried out by moving the essentially plane plate relative to the arrayof valves with a speed which is respectively adapted to the duration ofa process step, the rows Z_(m) respectively being arranged equallyseparated from one another and the rows Z_(m′) respectively beingarranged equally separated from one another.

Equal spacings of the rows from one another simplify the structure andproduction of the device. However, the outlay for driving theessentially plane plate with accelerated movements is greater.

A method for producing a device as described above includes theprovision of flow channels in the device as a function of thearrangement of the valves of the array in the n columns S_(n′) and mrows Z_(m). This permits a design of the device as a function of thevalves. Starting with the valves, which are more elaborate to produce,the flow channels and reaction chambers are then arranged or designed.An array of valves can thus be produced simply and economically alwayswith the same array shape by reusing the mold, it only being necessaryto establish the positions of the array at which valves are applied ornot applied. The channels and chambers, which are less expensive andsimpler to produce, are then defined and produced as a function of thevalves, the reactions to be carried out and the desired fluidics.Advantages in the costs of the design and the production can thus beachieved in a similar way to semiconductor electronics. In that case,components are arranged on a chip according to the purpose of a circuitand the production technology, and the interconnection is designed andproduced according to the position of the components. The components areelectrically connected to one another by the interconnection in such away that the desired electrical circuit is obtained.

The advantages associated with the method for controlling a device andwith the method for producing a device are similar to those which weredescribed above in relation to the device for controlling fluid flows inlab-on-a-chip systems.

Preferred embodiments with advantageous refinements will be explained inmore detail below with the aid of the figures, but without beingrestricted thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages will become more apparent andmore readily appreciated from the following description of the exemplaryembodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a schematic sectional view of the structure of a valve, and

FIGS. 2A-2C are a plan and two sectional views of a device forcontrolling fluid flows in lab-on-a-chip systems along the section lineA-A′ and along the section line B-B′ in FIG. 2A with an instrument forcontrolling the valves.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments,examples of which are illustrated in the accompanying drawings, whereinlike reference numerals refer to like elements throughout.

FIG. 1 shows a valve by way of example for better understanding of theinstrument for controlling fluid flows. The valve is constructed from abody 1 made of a plastic material and an elastomer compound 2. The body1 constitutes a support, or a substrate, and may have the form of a chipcard, an electrochemical sensor array for the detection of biochemicalsubstances being arranged on the embedded chip. For the sake ofsimplicity, the configuration of the chip card will not be discussed infurther detail here. Embodiments without a chip are also possible, forexample in optical analysis instruments.

A first recess 4 is formed in the support body 1. The first recess 4 isopen toward a front side 10 of the support body 1. It has the form of achannel and is used as a flow channel 4′. Liquids or gases can flowthrough the flow channel 4′. A second recess 3 is formed in directproximity to the first recess 4, adjacent to the flow channel. It has acommon interface with the first recess 4 in a subregion 9 of the firstrecess 4. The second recess 3, as shown in FIG. 1, is formedcontinuously from the front side 10 to the rear side 11 of the supportbody 1. It is fully filled, or occupied, with the elastomer compound 2.

A self-adhesive film 5 is applied flat on the front side 10 of thesupport body 1. The adhesive layer 6 of the self-adhesive film 5 ensuresgood adhesion of the film 5 on the support body 1 and on the elastomercompound 2. The film 5 with its adhesive layer 6, in conjunction withthe support body 1 and the elastomer compound 2, seals the flow channel4′ from the surroundings in an air- or gas-tight and/or liquid-tightfashion.

In order for the valve to be usable in biochemical devices, thematerials which come in contact with the liquids or gases must becompatible with the substances to be examined. Liquids used inbiochemical examinations are for example blood, urine, water, alcoholsor other solvents. Substances which, for example, are intended to beanalyzed or detected by biochemical devices are for example proteins,DNA or antibodies. These must not be influenced or modified by thematerials used.

Possible materials to be used for the support body 1 are hard polymers,which for the sake of simple production should be processable byinjection molding technology. The material should be plastic, i.e.difficult to deform or undeformable. Such materials are provided, forexample, by polycarbonate or polypropylene. In a prefabricated mold, thesupport body 1 of a chip card would be produced with its first recess 4and second recess 3 in one operation by injection molding technology. Ina second operation, the elastomer compound 2 would be introduced intothe second recess by injection molding technology. Thermoplasticelastomers, in particular, are suitable as possible materials for theelastomer compound 2. One example of a particularly highly suitablethermoplastic elastomer is a mixture of polypropylene and ethylenepropylene diene M-class elastomer, which is known by the brand nameSantoprene®.

A chip with a sensor array can be inserted from the rear side 11 intothe support body 1, which can be contacted and read out from the rearside by a reader unit 7. The front side of the support body 1, on whichthe flow channels 4′ and reaction chambers are arranged, may be fullycovered in a sterile fashion with the aid of a self-adhesive film. Thisprovides gas- and liquid-tight flow channels 4′ and reaction chambers.

One possible material for a film is polyethylene. It is, however, alsopossible to use other film materials.

FIG. 2 represents a device for controlling fluid flows in lab-on-a-chipsystems in a plan view and in sectional representations along thesection line A-A′ and along the section line B-B′ with an instrument forcontrolling the valves. The support or substrate body 1 with the valvesis fastened in a sandwich fashion in a reader unit 7. Parts of thereader unit 7 are pressed against the front side 10 and against the rearside 11 of the body 1. The body 1 is thereby mounted immobile in thereader unit 7. If the body 1 is configured in the form of a chip cardwith an electrical chip, then the reader unit 7 can read out and processsignals of the sensor array. A valve can be actuated by the reader unit7 in order to control fluidic processes and chemical reactions in thefirst recess 4 of the body 1.

As shown in FIG. 2 in the section B-B′, two valves, which arerepresented by way of example for the functionality of the valves, arearranged in the support or substrate body 1. Plungers 8 can put thevalves into an open state (right-hand valve I) or a closed state(left-hand valve II). A first recess 4, or a flow channel 4′, can beclosed in a liquid-tight and/or gas-tight fashion by actuating a valve.A plunger 8, which is arranged in the reader unit 7 and is controlled bythe latter, exerts a pressure force from the rear side 11 on theelastomer compound 2. This is done by moving the plunger 8 in thedirection of the elastomer compound 2. The pressure force, which isexerted by the plunger 8 on the elastomer compound 2, causes deformationof the elastomer. Since the elastomer can only expand in the directionof the first recess 4, it is pressed into the first recess 4. Thiscontinues until the first recess 4 is fully filled with elastomer alonga cross section of the first recess 4.

This in turn causes the valve to be closed.

If the plunger 8 is moved away from the elastomer compound 2, then lessto no pressure force acts on the elastomer so that the elastomer returnsto its original shape. The elastomer is retracted from the first recessand therefore frees it. The valve is opened again.

For simultaneous actuation of the valves, the plungers 8 are fastened ona fixed plate 7 a of the reader unit 7. The fixed plate 7 a lies on therear side 11 of the plastic body 1. The plungers 8 are prestressed toopening of the valves by a spring (not shown) so that they exert nopressure on the valves in this state. A plane plate with elevations 12is arranged movably behind the fixed plate 7 a of the reader unit 7.“Behind the fixed plate 7 a” refers to that side of the fixed plate 7 awhich lies on the other side from the body 1. If an elevation of themobile plane plate 12 lies immediately behind i.e. in contact with aplunger 8, then the latter is pressed in the direction of the elastomercompound 2 of the associated valve and the valve is closed. If there isno elevation of the mobile plane plate 12 behind a plunger 8, then theplunger is pressed, or prestressed, by the spring in the direction ofthe mobile plane plate 12 and exerts no pressure on the elastomer 2. Thevalve associated with the plunger 8 is opened.

The mobile plane plate with elevations 12, in conjunction with thereader unit 7, especially the fixed plate 7 a of the reader unit 7 withplungers 8, provides the instrument for actuating or controlling thevalves 13. The mobile plane plate with elevations 12 and the fixed plate7 a of the reader unit 7, as well as the plungers 8, are generally madeof a metal, for example steel, for stability reasons. Nevertheless,other solid materials such as hard plastic may also be used. The springsare generally made of spring steel.

Simultaneous actuation or non-actuation of all the valves of the arrayof valves according to a predetermined program is carried out by theinstrument for actuating the valves 13 and, in particular, by theessentially plane plate 12. When the mobile plane plate with elevations12 is moved relative to the fixed plate 7 a of the reader unit andtherefore relative to the plastic body 1 with the valves, valves belowwhich an elevation is inserted during the movement are actuatedaccording to the arrangement of the elevations on the plate 12. If aregion of the plate 12 without an elevation is inserted below a valve,the valve remains open. If an elevation lying below a valve is movedaway from below the valve and a region of the plate 12 is inserted belowthe valve in its place, the valve is opened.

By the arrangement of the valves in rows Z_(n) and columns S_(m) and theelevations in rows Z_(n′) and columns S_(m′), the spacing of the rows ofthe elevations being equal to the spacing of the columns of the valvearray, and by movement of the plate 12 along a direction which isparallel to a column, all the valves are actuated simultaneouslyaccording to a set program. Since only one valve is arranged in eachcolumn S_(m), an elevation only actuates a valve once. With a fixedpredetermined arrangement of the valves, the program is determined bythe arrangement of the elevations. A program step is determined byZ_(n′)=Z_(n) columns. When the plate 12 is moved through the spacing ofa row, the next program step is carried out according to the arrangementof the elevations in the next row. If a valve is intended to remainclosed between two program steps, then an elevation must be formedcontinuously along a column S_(n′) between two rows.

With uniform movement of the plate 12, with a fixed predeterminedspacing of the rows of the valves Z_(n), the duration of a program stepfor a predetermined constant speed of advance of the plate 12 relativeto the plate 7 a is determined by the spacing of the rows of theelevations Z_(n′). As an alternative, however, with predeterminedspacings of the rows of the elevations Z_(n′), the speed of advance maybe varied according to the desired duration of a process step.

As represented in FIG. 2 in the plan view, the valves are arranged onlyat particular points of the array of valves. Each column S_(m) has onlyone valve. An appropriate number of valves are arranged in a row Z_(n)according to the chemical reactions to be carried out and the desiredmicrofluidics. The flow channels and reaction chambers, the latter notbeing represented for the sake of simplicity, are formed as recesses inthe front side 10 of the plastic body 1 according to the arrangement ofthe valves. Complex chemical or biochemical reactions can thus becontrolled easily by the method described above. The program, whichcontrols the fluid flows by controlling the valves, is determined by thearrangement of the elevations on the plate 12. For the sake ofsimplicity, the valves in FIG. 2 are arranged with equal spacings fromone another in the columns S_(n) and rows Z_(m) in the body 1. Thevalves are all simultaneously controlled, i.e. actuated or not actuated,by the movement of the plate 12.

Other embodiments, which are not represented in the figures, for examplewith different spacings of the valves from one another in the columnsS_(n) and rows Z_(m) in the support or substrate body 1 made of plasticmaterial, may likewise be implemented. Control of the plungers 8 by theplate 12 may also be carried out using indentations instead ofelevations in the plate 12. In this case, an indentation corresponds toopening of a valve. It is also conceivable for the plungers 8 not to beprestressed so as to exert no pressure on a valve, but instead for themto be pressed onto the body 1 in the prestressed state or notprestressed at all. A reduced pressure may then contribute to movementof the plungers 8 over the plate 12.

A description has been provided with particular reference to preferredembodiments thereof and examples, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the claims which may include the phrase “at least one of A, B and C”as an alternative expression that means one or more of A, B and C may beused, contrary to the holding in Superguide v. DIRECTV, 358 F3d 870, 69USPQ2d 1865 (Fed. Cir. 2004).

1-13. (canceled)
 14. A device for controlling fluid flows in alab-on-a-chip system having flow channels, comprising an array of valvesarranged in n columns and m valve rows, where n and m are integers, eachvalve being configured to control fluid flow in an associated flowchannel, the array including at least two valves, each valve columnhaving at most one valve and each valve row having between zero and nvalves; and an instrument to actuate the valves.
 15. The device asclaimed in claim 14, wherein said instrument comprises an essentiallyplane plate having elevations projecting from the plane, in which n′plate columns and m′ plate rows are arranged, spacings of neighboringplate columns being equal to the spacings of associated neighboringvalve columns.
 16. The device as claimed in claim 15, wherein theessentially plane plate is mounted movably in a first direction relativeto the array of valves, the first direction extending parallel to thevalve columns of the array of valves.
 17. The device as claimed in claim16, wherein the elevations project from the plane of the plate, arrangedin n′ plate columns and m′ plate rows, so that some valves are closedand other valves are opened in a controlled way according to apredetermined program during a movement of the essentially plane platealong the first direction relative to the array of valves.
 18. Thedevice as claimed in claim 17, wherein the array of valves is arrangedin a chip card comprising a flat body made of a plastic material incredit card form, having a front side on which a self-adhesive film isapplied, wherein the flow channels are arranged in the flat body asrecesses on the front side, and wherein the valves contain an elastomercompound arranged at least partially next to a respectively associatedflow channel.
 19. The device as claimed in claim 18, wherein the flatbody consists of at least one of polycarbonate and polypropylene. 20.The device as claimed in claim 18, wherein the elastomer is athermoplastic elastomer formed of one of rubber and a mixture ofpolypropylene and ethylene propylene diene M-class elastomer.
 21. Thedevice as claimed in claim 18, wherein the chip card is arranged in asandwich fashion in the instrument and includes an instrument plate on arear side of the chip card, and further comprising: plungerscorresponding to the valves and respectively actuating the valves, theplungers arranged on the rear side of the chip card in the instrumentplate, and springs, each plunger prestressed by at least one of thesprings disposed between the instrument plate and the plunger so thatsubstantially no pressure force exists between the plunger and acorresponding valve.
 22. A method for controlling a device as claimed inclaim 21, wherein the valves are respectively actuated by application ofa pressure force, exerted by at least one plunger, to close each valvecorresponding to the at least one plunger, thereby preventing a fluidfrom flowing in the respectively associated flow channel, and whereinwhen the pressure force is not applied to a corresponding valve, thecorresponding valve is opened and the fluid flows in the respectivelyassociated flow channel.
 23. The method as claimed in claim 22, whereinthe valves are opened and closed in accordance with a predeterminedprogram by moving the essentially plane plate parallel to the valvecolumns relative to the array of valves.
 24. The method as claimed inclaim 23, wherein the difference between the m′ plate rows of theessentially plane plate and the m valve rows of the array of valvesdefines a number of process steps in which at least one valve isactuated.
 25. The method as claimed in claim 24, wherein there is equalspacing between each of the valve rows, and wherein when the essentiallyplane plate is moved relative to the array of valves with a fixed speed,a duration of each process step is determined by spacing between theplate rows.
 26. The method as claimed in claim 24, wherein there isequal spacing between each of the plate rows, and wherein when theessentially plane plate is moved relative to the array of valves with afixed speed, a duration of each process step is determined by thespacing of the valve rows.
 27. The method as claimed in claim 24,wherein there is a first consistent spacing between each of the platerows and a second consistent spacing between each of the valve rows, andwherein the essentially plane plate is moved relative to the array ofvalves with a speed respectively adapted to a duration of a processstep.
 28. A method for producing a device as claimed in claim 21,wherein the flow channels are provided as a function of an arrangementof the valves in the n valve columns and m valve rows.